def main(X):
    if X >= 30:
        return 'Yes'
    else:
        return 'No'

if __name__ == '__main__':
    X = int(input())
    ans = main(X)
    print(ans)
 def main(X):
    if X >= 30:
        return 'Yes'
    else:
        return 'No' main if X >= 30:
        return 'Yes'
    else:
        return 'No' X >= 30 X 30 return 'Yes' 'Yes' return 'No' 'No' X X if __name__ == '__main__':
    X = int(input())
    ans = main(X)
    print(ans) __name__ == '__main__' __name__ '__main__' X = int(input()) X int(input()) int input() input ans = main(X) ans main(X) main X print(ans) print ans ans = main(X) main(X) ans def main(X):
    if X >= 30:
        return 'Yes'
    else:
        return 'No' def main(X):
    if X >= 30:
        return 'Yes'
    else:
        return 'No' main X = int(input()) int(input()) X
def main(X):
    if X >= 30:
        return 'Yes'
    else:
        return 'No'

if __name__ == '__main__':
    X = int(input())
    ans = main(X)
    print(ans)

